The present invention relates to Bit-Interleaved Coded Modulation (BICM) for CATV upstream channels.
Upstream CATV channel suffer from a hostile environment that includes various impairments. Such impairments include additive Gaussian white noise (AWGN), impulse noise, bust noise, narrowband noise (ingress) and others. The present invention provides a coding scheme that is robust to these impairments, especially impulse noise and AWGN. The complexity of the encoder of this method is relatively low, which makes it ideal for multi-point to-point channels, such as the CATV upstream channel.
The present invention is a coding scheme that includes a convolutional encoder, bit-interleaver and symbol mapper. The parameters of these units are determined as a trade off between data throughput and system robustness, according to the channel conditions. The circuitry to build the encoder are low cost and widely used. Simulations have shown that the provided method is very efficient for CATV upstream channels in many typical scenarios, including AWGN, impulse noise, burst noise and combinations of these channel impairments.